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use super::*;
#[derive(Debug, Clone)]
pub struct Record {
pub values: Vec<Value>,
pub tombstone: bool,
}
impl Record {
pub fn serialize(&self) -> Vec<u8> {
let mut bytes = Vec::new();
if self.tombstone {
bytes.extend(&[B_TOMBSTONE]);
} else {
bytes.extend(&[B_LIVE]);
}
for value in &self.values {
bytes.extend(value.serialize());
}
bytes
}
pub fn deserialize(bytes: &[u8]) -> Record {
assert!(bytes.len() > 0);
let mut values = Vec::new();
let tombstone = bytes[0] == B_TOMBSTONE;
let mut start = 1;
while start < bytes.len() {
let (rv, consumed) = Value::deserialize(&bytes[start..]);
values.push(rv);
start += consumed;
}
Record { values, tombstone }
}
pub fn from(values: &[Value]) -> Record {
Record {
values: values.to_vec(),
tombstone: false,
}
}
pub fn at(&self, index: usize) -> &Value {
&self.values[index]
}
pub fn validate<Field: Eq>(&self, schema: &[(Field, Type)]) -> DBResult<()> {
// If there are more values than schema fields, it's an error.
if self.values.len() > schema.len() {
return Err(DBError::ValidationError(format!(
"Record has more fields ({}) than expected by the schema ({})",
self.values.len(),
schema.len()
)));
}
for (i, (_, typ)) in schema.iter().enumerate() {
match self.values.get(i) {
Some(value) => {
if !Self::value_matches_type(value, typ) {
return Err(DBError::ValidationError(format!(
"Record field {} has incorrect type: {:?}, expected {:?}",
i, value, typ.primitive
)));
}
}
// If the field is missing from the record...
None => {
// ...it's allowed only if the schema says the field is nullable.
if !typ.nullable {
return Err(DBError::ValidationError(format!(
"Record is missing field expected by the schema ({:?}) at index {}",
typ, i
)));
}
}
}
}
Ok(())
}
fn value_matches_type(value: &Value, typ: &Type) -> bool {
match (value, typ) {
(Value::Null, Type { nullable: true, .. }) => true,
(
Value::Int(_),
Type {
primitive: PrimitiveType::Int,
..
},
) => true,
(
Value::String(_),
Type {
primitive: PrimitiveType::String,
..
},
) => true,
(
Value::Bytes(_),
Type {
primitive: PrimitiveType::Bytes,
..
},
) => true,
_ => false,
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_record_serialize_deserialize() {
let record = Record {
values: vec![
Value::Int(1),
Value::String("hello".to_string()),
Value::Bytes(vec![0, 1, 2, 3]),
],
tombstone: true,
};
let serialized = record.serialize();
let deserialized = Record::deserialize(&serialized);
let reserialized = deserialized.serialize();
assert_eq!(serialized.len(), reserialized.len());
assert_eq!(record.values, deserialized.values);
}
}
#[derive(Clone, Debug)]
pub enum TxEntry {
Upsert { record: Record },
Delete { record: Record },
}
|
